The present invention relates to printers, and more specifically, to apparatus and methods for printing on a card with high precision.
Thermal printers are used for printing various documents including personal identification cards. Typically, these identification cards have images on their surfaces printed in various colors. Some cards have images printed in metallic color. Further, some cards have a lenticular lens thereon so that a user can see different images depending on the viewing angle with respect to the normal direction of the surface of the card.
In the prior art, when an image sheet having printed images thereon is affixed onto a plastic sheet having a lenticular lens thereon, alignment of these two sheets requires high precision. Misalignment of the image sheet and the lenticular lens sheet would result in mixed or blurred images of the two separate images. In a normal lenticular card, only one of the two images can be seen if the user fixes the point of view. In order to align the image sheet with the lenticular sheet, the prior art technique requires a skilled worker to manually align the two sheets. This is a time-consuming task, and thus incurs cost. Besides, due to the manual alignment, the yield of the resulting product is low.
In view of these and other issues, it would be desirable to have a technique allowing a printer to print images with high precision.
According to various embodiments of the present invention, a printer prints images on a printing medium having a mark. The printer includes an optical sensor, a feeding section, a controller, and a printing section. The optical sensor is operable to generate a signal based on a position of the mark of the printing medium with respect to the optical sensor. The feeding section is operable to perform feeding of the printing medium. The controller is operable to control the feeding of the printing medium based on the signal. The printing section is operable to print images on the printing medium.
In a specific embodiment, the sensor is a linear optical sensor which is operable to detect the mark provided on the printing medium. Based on a signal output from the sensor, the controller aligns the printing medium with the images printed on the medium using the feeding section.
In some embodiments, the mark is a line or a stripe drawn on the printing medium diagonally with respect to the line.
In some specific embodiments, the printing section includes an intermediate transfer film, a print head, and an intermediate transfer roller. The print head has a plurality of resistance heating elements for transfer of the ink from the ink film to the intermediate transfer film. The intermediate transfer roller is operable to heat the ink on the intermediate transfer film for transfer of the ink from the intermediate transfer film to the printing medium.
A further understanding of the nature and advantages of the present invention may be realized by reference to the remaining portions of the specification and the drawings.